Chalcogenide Letters Vol. 10, No. 7, July 2013, p. 239 - 246 THICKNESS DEPENDENT PROPERTIES OF n-CdSe THIN FILMS FABRICATED BY ELECTRON BEAM EVAPORATION TECHNIQUE. S. R. VISHWAKARMA * , ANIL KUMAR, SASMITA DAS, A. K. VERMA, R. S. N. TRIPATHI Department of Physics & Electronics, Dr. R. M. L.Avadh University,Faizabad - 224001,India. India The nano crystalline semiconducting thin films of n-CdSe having different thicknesses have been fabricated on glass substrate at room temperature by electron beam evaporation technique using optimized source material. Thicknesses of the n-CdSe thin films arein the range of 600nm to 1200nm. The variations of electrical, optical and structural properties of n-CdSe thin films with thickness have been studied. The structural property of thin films has studied by X-ray diffractometer which revealsthat films have polycrystallinehexagonal structure with preferred orientation (002) plane. The surface morphology of films has also been studied by scanning electron microscope. The morphological and crystalline studies revealed that the thin film surface and crystallinity of the grains in films were improved with increase of film thickness. The optical band gaps are calculated for films using absorption coefficient. The electrical resistivity and activation energyof n-CdSe thin films are calculated by four probe resistivity measurement. Thecarrier concentration and Hall mobility of n-CdSe thin films are calculated by Hall measurement. The dependence of electrical parameters ofn-CdSe films on thickness has also been studied. Thus the thickness of n-CdSe thin film 1000 nm is optimized on the basis of structural, optical and electrical properties. (Received May 5, 2013; Accepted July 10, 2013) Keywords: Fabrication & characterization, n-CdSe thin film, Thickness, Grain size, Lattice parameter 1. Introduction The electrical, structural and optical properties of II-VI compound semiconductors have been found suitable for the preparation of semiconducting devices especially photo detector and solar energy converter. The cadmium selenide (CdSe) is one of the promising materials of this group used for fabrication of efficient multilayer thin film solar cell due to their high photosensitive property [1]. The CdSe compound semiconductor is also used in the fabrication of different optoelectronic devices [2-4]. The CdSe thin films possess n-type as well as p-type semi conductivity depending upon the type of vacancies created during deposition of thin films. The direct band gap of CdSe is 1.74 eV with hexagonal structure [5]. The quality of CdSe devices strongly depends upon electrical and structural properties of thin film fabricated with different experimental techniques. These techniques are vacuum or non-vacuum [6,7], laser ablation [8], electro chemical deposition [9], chemical deposition [10], hot wall deposition [11] and spray pyrolysis [12].The electron beam evaporation technique is suitable for the deposition of n-CdSe thin films due to high power density, wide range of controlled evaporation as well as directly evaporent material converted into vapour [13]. During the deposition process, evaporent material is placed in water cooled graphite crucible, in this process only its upper surface get high * Corresponding author: srvfzb@rediffmail.com